17β-estradiol (βE2) protects human retinal Müller cell against oxidative stress in vitro: Evaluation of its effects on gene expression by cDNA microarray

17β‐estradiol (βE2) is an effective neuroprotectant against hydrogen peroxide (H2O2)‐induced retinal neuronal cell death and light‐induced photoreceptor degeneration. Müller cells are the principal macroglia responsible for supporting retinal neuronal survival, information processing and removing metabolic waste. However, the role of βE2 on human Müller cells is unclear. In this study, the effects of βE2 on human Müller cell survival and gene expression were examined. Our data revealed that βE2 is able to increase human Müller cell viability after exposure to H2O2 through inhibition of apoptosis. Microarray analysis revealed significant changes in the expression of 69 genes (total of 21,324 genes screened) in cultured human Müller cells 6 h after βE2 treatment. Four of the βE2‐responsive genes [thrombospondin 1 (TSP1), mitogen‐activated protein kinase kinase kinase 3 (MAP3K3), large conductance calcium‐activated potassium channel β2 subunit (KCNMB2), and SRY (sex‐determining region Y)‐box 11 (SOX11)] were validated by both real‐time qRT‐PCR and semi‐quantitative RT‐PCR. Interestingly, exposure of human Müller cells to βE2 increased pigment epithelium‐derived factor (PEDF) gene expression as measured by both RT‐PCR and real time qRT‐PCR. Our data demonstrate, for the first time, that βE2 protects cultured human Müller cells against H2O2‐induced cell death through the inhibition of apoptosis. This protective effect may operate through regulation of genes, such as TSP1, MAP3K3, SOX11, TSP1, and PEDF, and may in turn exert an important role in protecting retinal neurons. © 2005 Wiley‐Liss, Inc.